VR6 - Start Problem (ECU related)

[mattwelcer 0]

I have a odd start problem with my VR6

 

I appear to be getting no voltage at the fuel pump (roughly 0.9V) and the relay doesn't click. If I remove the relay and bridge the large pins 87 + 30 (bypassing the relay) the fuel pump has 12V and runs.

 

So I checked the pins at the relay and the one that appears to be the problem is Position 85 which comes from the ECU and I believe it is ground (wire colour Yellow/Blue).

On the ECU this is PIN 6, if I ground this pin to the battery (using a probe in the back of the pin with a cable directly to the negative terminal on the battery) then you can hear the relay click and the fuel pump runs. Also if the voltage is measured at the pump then it shows battery voltage and the car starts fine. So this to me rules out bad wiring from pin 6 of the ECU to the plug on the back of the relay panel and the relay/fuse panel itself.

 

Today I received another ECU with the same part number, plugged it in expecting everything OK but I still have the same problem.

 

Therefore what tells the ECU to give ground to pin 6? As once the car is started it runs fine and doesn't cut out while driving.

[seanl82 23]

I thought by swapping out the ECU, you need the immobiliser ring for ignition as well? I was gonna suggest that it could well be an immobiliser fault until you mentioned that it starts fine when bypassing direct to the pump, as the immob cuts both fuel and spark I believe......